An Australian scientist involved in the search for weapons of mass destruction in Iraq has claimed the U.S. Central Intelligence Agency doctored his reports to suggest that such weapons existed when they did not. Rod Barton, a microbiologist, has told Australian television he quit the Iraq Survey Group in disgust at the censorship of its interim report presented to the U.S. Congress last March.

Rod Barton joined the search for Saddam Hussein's weapons of mass destruction, or WMD, after the first Gulf war in 1991.

When the Iraqi dictator was deposed in 2003, the Australian microbiologist was among a thousand inspectors deployed by the United States to scour the country for his illicit arsenal.

No weapons of mass destruction were found and there was no sign that any such programs were being developed. In an Australian news broadcast Monday, Mr. Barton said he was not allowed to tell the truth about the inspectors conclusion after their exhaustive search in Iraq.

Mr. Barton claims that U.S. censorship of his reports began in February 2004 after Charles Duelfer became the new head of the U.S.-led Iraq Survey Group. He alleges that Mr. Duelfer wanted the WMD report to be vague and inconclusive and to omit politically sensitive information.

The former weapons hunter told the Australian Broadcasting Corporation's "Four Corners" television program that the report issued last March was not accurate.

"We left the impression that, yes, maybe there were WMD out there, maybe there were programs still to find, and all our future work might discover this," said Mr. Barton. "So I thought it was dishonest. I was part of the dishonesty by being there, by continuing on with this, and so although I quite enjoyed the work, I did leave."

Mr. Barton illustrates his claims with the case of aluminum pipes found in Iraq. He says the report was not allowed to mention that they probably were not part of a nuclear weapons program.

The pipes had earlier been described as possible components for centrifuges to be used for nuclear enrichment. They were highlighted by the United States in building the case for war against Iraq.

At the end of March last year, Charles Duelfer presented the Iraq Survey Group's interim report to the U.S. Congress. He stated that he continued to "receive reports all the time that there are hidden weapons" in Iraq to be pursued.

By then Mr. Barton had resigned and had left Baghdad.

He later returned to Iraq at the request of Mr. Duelfer, who said he was working on a "final, honest report." Mr. Barton says he is satisfied with that report, which was issued last October. It said Saddam had no weapons of mass destruction, had not made any since 1991 and had no capability of making any.

So far, there has been no comment from Washington, Canberra, or Mr. Duelfer on Mr. Barton's interview.